1. Field of the Invention
This invention relates to novel attractants for the Mediterranean Fruit Fly, Ceratitis capitata Wiedmann, hereinafter referred to as the "Medfly." More particularly, the present invention relates to novel isomeric blends of aliphatic esters of iodo-trans-2-methylcyclohexanecarboxylic acid, the method of their preparation and the method of use thereof to attract the Medfly for prolonged periods of time.
2. Description of the Prior Art
Attacking over 250 varieties of fruits, nuts and vegetables, the Medfly is one of our most serious crop pests. Found predominately in Hawaii, Central America, and subtropical regions of the world, the Medfly has periodically invaded the mainland of the United States causing major economic losses. Consequently, there exists a great need for effective programs to control this pest.
Several attractants for the Medfly are known. Siglure (1-methylpropyl trans-6-methyl-3-cyclohexenecarboxylate) was the first synthetic lure found to have significant attraction to the Medfly. Medlure (1-methylpropyl 4(and 5)-chloro-trans-2-methylcyclohexanecarboxylate) and trimedlure (1,1-dimethylethyl 4(and 5)-chloro-trans-2-methylcyclohexanecarboxylate), hereinafter referred to as "TML," were later reported to be greatly superior as Medfly attractants.
Currently, TML is the "standard" attractant most widely used in traps for survey and detection of the Medfly. TML evaporates rapidly during hot weather thereby necessitating frequent and costly rebaiting of the traps. Further, the short residual life of TML (as well as Medlure and Siglure) mitigates against the development of an economical male-annihilation formulation of attractant plus insecticide. TML also forms crystals during cold-weather storage so that the amount of the attractant is reduced in the supernatant. Because these crystals do not readily redissolve, special storage problems can occur in larger volume programs.